Electric fuse.



PATENTED MAR. 27, 1906.

B. S. LUTHER. ELECTRIC FUSE. APPLICATION FILED APR.z4,19o5.

nnnilrnn n sean/'Mor nnwsnnrro br5 i o Barron o No. einem.

Specieaton of Letters '.zatent.

atentecl March 27, 1996.

Application tiled April Z4, 5.905. Serial No. 267,119.

To @ZZ whom it Ilm/y; .fwn/cern:

Be it known that l, Bernardin S. Lnrnnn, of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Electric Fuses, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

Electric fuses es ordinarily manufactured corn rise a tuhular cylindrical shell 'or case of insu ating material and metallic caps litt-ed upon the opposite ends thereof, which are secured thereto by short pins driven through' holes in the caps into the shell or case. This method of securing the end caps tothe shell or case is very objectionable for inany reasons as, for instance, the pins are very small and di'llicult to handle, they frequently loosen and fall out, owing to the shrinkage of the shell or case, and when driven into the shell or case the heads thereof forni projections on the cylindrical body portion of the end caps which ol'ler obstructions when thrusting (ii-*sliding the fuses into certain forms of end supports adapted to receive them, whereupon said heads are first renioved, leaving only the Shanks ofthe pins to hold the end caps.

This invention has for its object to provide means for securing the end caps to the shell or `ease which are not liable to loosen and `which are located within the caps, so that no external projections are formed on the cylindrical body portion thereof.

The invention consists, essentially, in cutting and projecting inwardly into-tlie material of the shell or case integral portions of the cap, whiehportions are formed as spurs with chisel-pointed ends and approximately direction toward the out-erelid of the cap.

Figure l shows in side elevation a sufficient portieri of an electric fuse to illustrate my in' posed spurs or integral parallel sides and which are extendedin a ends thereof. To secure the end cap to the shell or case in accordance with Iny inven? tion, the cap will be placed thereon and by a suitable tool an integral portion ofthe cylindrical body of the cap will be cut and projected inward into the material of the shell or case. The punching-tool will be made of suitable shape to produce a small rectan lar hole, as b', (see Fig. 1,) in the cylin rical body of the cap and to out three sides of said hole and to drive in trie material from the other side, so that the integral po'rtion thus cut and bent inward vill forin-V a spur, as 52, A(see Figs. 2, 3, and 5) with approximately parallel sides and with a chisel-pointed end. The end of the spur is formed with a chiselpoint by the material thereof being drawn from it as the s ur is formed. The spur (-22 will project inward from that end of the hole b remote from the outer'cnd of the cap, hence will extend in a direction toward theouter end of the cap, and wheiry so extended will Vprevent the cap from being pulled oll` of the shell or case, it being understood that as the. s ur is projected into the material of the sliell or case by the punching-tool said niaterial will have atendency to crowd in and around the spur and thereby essentially e1nbed the spur, inthe material of the shell or case. The caps will be secured by as many spurs as desired-as, for instance, the caps of a fuse of ordinary size will have four spurs.

yThe spurs thus fornicd being integral with theicap cannot fall out, and, furthermore7 being formed within the cap toe cylindrical body thereof is devoid of external projections.

Referring to Fig. 4i, two. oppositely-disortions are cut and rejected into the shell or body. In this forni the punching-tool which acts upon the cap will forni a rectangular hole, cutting two sides of it and bending inward lthe other two sides.

Having thus described my invention, what l claim as new, and desire to secure by Letters Patent, is-

l. In an electric fuse, a cylindrical shell or case, an end cap thereon having integral portions thereof Vwith approximately parallel -sides and chiselspointed ends 'cut and pro jected inward into the material of the lshell or case, substantially as described.

IOS

2. ln au eleetrouse, a cylindrical shell or name to this specification in the presence of ase, :(1111 end cap thereon havdng ntlgrally two subscribing Witnesses.

orme s urs ro'eetet nwar into t e ma- T f terial of he shel or case, and extended ob BENJAMIN S LUTHER' 5 lquely in a direction toward the outer end Witnesses:

thereof, substantially as described. L. H. HARR'IMA'N,

In testimony whereof I have signed my B. J. N OYEs. 

